Cylinder drive control and safety means



Feb. 28, 1961 E. F. DUDLEY CYLINDER DRIVE CONTROL AND SAFETY MEANS INV EN TOR. rdf/deky,

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Feb. 28, 1961 E. F. DUDLEY 2,972,945

CYLINDER DRIVE CONTROL AND SAFETY MEANS Filed March 24, 1958 3 Sheets-Sheet 2 INVENTOR.

Feb. 28, 1961 E. F. DUDLEY 2,972,945

CYLINDER DRIVE CONTROL AND SAFETY MEANS Filed March 24, 1958 3 Sheets-Sheet 3 mnnl@ nited States CYLINDER DRWJE CNTROL AND SAFETY MEANS Filed Mar. 24, 1958, Ser. No. 723,393

4 Claims. (Cl. 101282) The invention relates to printing presses and has reference in particular to cylinder drive control and safety means for the type of printing press wherein the type bed and impression cylinder have relative vertical reciprocating movements.

In Patent No. 1,587,513, granted June 8, 1926, and entitled Cylinder Safety Means there is disclosed a vertical type of printing press having cylinder safety means to prevent the impression cylinder from becoming disconnected from its rotary driving gear during a printing stroke. Although theoretically the structure appears to be foolproof, nevertheless it is mechanically possible for the cylinder to become disconnected from the driving gear and which will most `likely take place near the end of its printing movement `and before the main driving y cranks have reached a dead center position.

Accordingly an object of the present invention is to provide cylinder drive control and safety means for positively maintaining the impression cylinder locked to its rotary driving gear during the entire printing stroke of the press.

Another object is to provide more efcient and durable safety means for the impression cylinder of the vertical type of printing press as described.

With these and other objects in view, the invention may consist of certain novel features of construction and operation as will be more fully described and particularly pointed out in the specification, drawings and claims appended thereto.

In the drawings which illustrate an embodiment of the invention and wherein lise reference characters are used to designate like parts- Figure 1 is a side elevational View of avertical type of printing press embodying 'the improvements of the invention;

Figure 2 is a fragmentary side elevational View of the journalling structure at one end of the impression cylinder of the press;

Figure 3 is an end elevational view of the structure as shown in Figure 2;

Figure 4 is a sectional view taken substantially along line 4 4 of Figure 2 and looking in the direction of the arrows;

Figure 5 is a sectional view similar to Figure 4 but showing a shifted position of the rotatable collar;

Figure 6 is a fragmentary view showing in side elevation the ratchet wheel and pawl for locking the impression cylinder to its driving gear;

Figure 7 is a sectional view taken transversely of the impression cylinder and illustrating structural details associated with the pawl and ratchet wheel; and

Figure 8 is a fragmentary View sho-wing in detail the coaction which the cam arm has with the rotatable collar.

A vertical type of printing press such as may embody the improvements of the present invention is shown in Figure 1, wherein a main frame it) has mounted thereon the wayframe including two vertically arranged side members 11. Mounted on the way-frame members 11 in approximately mid-position vertically thereof are a pair of spaced gears 12, the said gears being rotatably supported by the trunnion 13. Said gears 12 are thus journalled by members 11, which members in -addition provide ways for the reciprocable type bed 16. Secured to the rear of the type bed 16 on respective sides thereof are the racks 18 which have meshing relation with the gears 12, respectively, for driving purposes to be referred to later. By means of pins i9 the connecting rods 20 are joined to the racks 18 and said rods in turn are pivotally connected to the cranks 21 of a drive shaft 22 mounted in the main frame lil of the press.

An impression cylinder 23 is rotatably journalled in the side arms Z4 of the cylinder frame 25, which is also mounted on the members 11 by means, not shown, so as to reciprocate vertically with respect to said members. The structure for mounting the cylinder frame 25 provides the racks 26 at the sides of the frame and which project rearwardly to have meshing relation with the gears 12, respectively. Thus when the press is in operation the connecting rods 20 transmit a driving force from shaft 22 to the racks 18 which divide the force, part thereof being applied directly to the type bed to reciprocate the bed and part being transmitted by the gears 12 to the racks 26 so that the cylinder frame 25 is also reciprocated but in directions opposite to that of the type bed. In other words, as the type bed 16 moves upwardly the cylinder frame 25 will be caused to move downwardly and vice versa.

On the front face of the type bed there is provided an additional rack indicated by numeral Sil, and the impression cylinder 23 at one end thereof is equipped with a driving gear 31. This structure is illustrated in Figures 1 and 6 and it Will be understood that the drivinggear 31 meshes with the rack Sil so that the gear is driven thereby. Said driving gear 31 is loosely and rotatably mounted on the impression cylinder 23 so that the gear may be rotated as a result of relative movement with respect to the rack 30 without rotary movement being transmitted to the cylinder proper. As the cylinder frame 25 and impression cylinder 23 move downwardly from the upper position, as shown in Figure l, it will be understood that driving gear 31 will be rotated in a clockwise direction. Conversely, as the cylinder frame 25 and impression cylinder 23 move in an upward direction the driving gear 31 will be rotated in a counterclockwise direction.

To rotate the impression cylinder 23 a positive connection between said cylinder and gear is necessary. This positive connection takes the form of a pawl 32 having a head 33 adapted to enter the single notch 34 of a ratchet wheel 3S, all as best shown in Figures 4, 5 and 6. The said ratchet wheel is secured to the driving gear 31 within the periphery of the same and'said pawl 32 is fixed to a shaft 36 carried and journalled by the end walls of the impression cylinder 23, and positioned eccentrically with respect to the longitudinal axis of said cylinder. Accordingly, when the pawl head 33 is held in the notch 34 of the ratchet wheel 35 and the cylinder is moving upwardly, the said impression cylinder will be rotated in a counterclockwise direction as viewed in Figure l, by virtue of the gear 31 meshing with the downwardly moving rack Sil. The pawl head 33 is pressed against the annular edge of the ratchet wheel 35 and more particularly said pawl head 33 is pressed into and held in notch 34 during the upward stroke of the cylinder by coil spring 37, Figure 7, which is coiled around a suitably supported rod 38 having a pivotal connection with an arm 39 secured to shaft 36. So long as the pawl head 33 remains in notch 34 and the cylinder 23,

3 is moving upwardly the said impression cylinder will be rotated.

When the cylinder comes to rest momentarily at the top dead center position, it is locked against angular displacement by suitable stops, not shown. These stops are effective to hold the cylinder against rotary movement while it is at the top dead center position of its cycle and until it has moved a short distance on its downward stroke. Consequently, as the cylinder assembly begins to move downwardly, the gear 31 is rotated in a clockwise direction, but since the cylinder is temporarily locked against rotation therewith, the pawl head 33 is forced out of the notch 34 against the tension of spring 37 and it rides on the peripheral surface of the rotating ratchet Wheel 35 until the ratchet wheel reaches the bottom dead center of its downward stroke. At this point the gear 31 and ratchet wheel 35 will have made one complete revolution and the pawl head 33 will once again be aligned with the notch 34. The force exerted by the spring 37 causes the head 33 to enter the notch 34 at this point so that the cylinder is engaged with the drive gear and thus will rotate on its upward stroke.

lTo facilitate disengagement of the pawl head from the notch as the cylinder starts its downward stroke, it will be noted that the face dit of the pawl head and the coacting wall 41 of the notch are bevelled as shown in Figures 4 and S.

When the mechanism is operated at high speeds, it is entirely possible for the impression cylinder to become disconnected prematurely from its drive means. Such an occurrence has actually taken place and is due to the inertia of the cylinder which when the cylinder is being decelerated, tends to cause the cylinder to overtravel with respect to the driving gear 31. The bevelled surfaces 40 and 4i afford a minimum of resistance against the force of inertia and therefore, the pawl head 33 may be forced out of the notch 34 against the pressure of spring 37 before the cylinder reaches the top dead center position.

As disclosed in said Patent No. 1,587,513 means have been provided for locking the pawl head in its notch during upward rotative movement of the cylinder. However, there is a most critical period when the pawl head tends to become disengaged, namely, when the shoe 42 of the locking means, as shown in Figure 4, leaves the collar i3 and enters the slot 44 provided therefor in said collar. The shoe 42 is carried by lever 4S which is fixed to the end of shaft 36 opposite the pawl 32.

A premature or accidental disconnection of the pawl 32 from notch 3ft is undesirable for a number of reasons. First of all, the connecting rods lose control of the cylinder before reaching dead center and some additional means would have to be provided to slow down the rotation of the cylinder and bring the same to a complete stop. The loss in control of the impression cylinder by the main driving shaft may amount to as much as twenty degrees of travel of the crank 21. Secondly, in operating the press at various speeds the loss as regards control of the impression cylinder may vary, thus causing the cylinder to be out of exact timing with the delivery mechanism. In order to insure against any disconnection of the impression cylinder and its driving gear, except as required for proper operation of the parts, additional safety means are provided by the present invention and which are shown in detail in Figures 2 and 3. it has been previously explained that the lever 45, which is secured to shaft 36, is provided with the stud or shoe 42, and which is adapted to pass inwardly through slot 44 intothe groove te when the pawl head 33 is raised out of its notch 3d at the upper limit of movement of the impression cylinder. The shoe 42 remains within the groove 46 during downward movement of the cylinder but does not rotate with respect thereto for the reason that the cylinder is not rotated, In the present construction instead of the collar 43, which provides the iiange 47, being iixed against rotation on a part of the impression cylinder frame, the said collar 43 is mounted for limited rotation or angular displacement about the axis of the cylinder journal, as shown in Figures 2 and 3, and means are provided for displacing said collar 43 at the critical period in the vertical reciprocating movements of the impression cylinder to positively prevent accidental disengagement of the pawl head 33 from the notch 34.

The impression cylinder 23 is journalled by the trunnions 4S in the side arms 2e of the cylinder frame 25 and rotatably mounted on the right hand trunnion, as shown in Figure 2. between the cylinder 23 and arm 24, is the collar 43. The lever 45, fixed to shaft 36 and having the shoe 42, is adapted to coact with the flange 47 of the collar 43 in a manner to maintain the pawl 32, at the opposite end of the shaft 36, located in its notch 34. -To release the pawl it is necessary for the shoe to enter slot 44 and pass into the groove 46.

For temporarily displacing the collar angularly about the trunnion 48 in order to shift the slot 44 from its normal release position with respect to shoe 42, the invention provides a stud shaft 52 journalled by the side arm 24 and extending to the collar 43 at which end the stud shaft is provided with the cam arm 53. The said cam arm enters the opening Sli in the collar i3 which is of a size to just receive the cam arm so that any movement of the cam arm about the axis of the stud shaft 52 will be transmitted to the collar. A lever S5 is fixed to the projecting end of the stud shaft 52 and said lever is pivotally connected at 56 to the rod S7 having its lower end extending through a support 53 suitably secured to the side arm 24. A stop 60 is xed to the depending end of rod 57 and the coil spring 6l is carried thereby in a manner to tension the parts and maintain the rod and lever in an up position, as shown in Figure 3. In this position the cam arm 53 is approximately horizontal and the collar 43 is normally located with the slot 44 in the release position as regards the shoe 42 as shown in Figure 4. A cam operated rod 62 is mounted on the members 11 by the supports 63 and 64 with an extension 65 being lixed to the rod immediately below support 63 but above lever 55 so as to contact said lever during a certain period in the operation of the parts. The rod 62 extends into the frame it) and is pivotally connected at 66 to the lever 67 supported at 68 and which carries roller 69 at its right hand end. The said roller is camrned at predetermined times by the high portion 7u of a cam 71 and the said roller end is horizontally held in rolling contact with cam 71 by tensioning spring '72. The cam 7ll is driven in timed relation to the reciprocating movements of the impression cylinder by means of a gear 73 mounted on the cam shaft 74 and which meshes with the drive gear '7S on the crank shaft 22.

When the impression cylinder 23 has reached its lower limit of movement and is about to start on its upward printing movement the pawl head 33 is moved into notch 34 and accordingly shoe 42 will be moved outwardly through slot 44. As the cylinder rotates under these conditions the shoe 42 rides on the outer surface of flange 47, and thus it is impossible for the pawl 32 to move out of its notch. ln fact, the flange will not permit an inward movement of the shoe 42 until the cylinder has nearly completed its upward rotary printing movement, when the shoe is again presented to the slot 44. However, in advance of this occurrence, the collar 43 is angularly displaced so as to shift the slot 44 from its normal release position with respect to the shoe to thereby prevent'the pawl 32 from becoming disengaged from its notch 34 until the cylinder is at rest at the top dead center position. The angular position of collar 43 l is changed as the impression cylinder approaches its top limit of travel. At this point in the upward movement of the cylinder the rod 62 is cammed in a downward direction by virtue of the cam 71 and by thus lowering the extension 65 the lever 55 is caused to contact the same. As the iinal upward movement of the impression cylinder continues the lever 55 is rocked to in turn rock the cam arm 53 and rotate the collar i3 in a counterclockwise direction as illustrated in Figure 5. When the main driving cranks 21 reach lower dead center the rod 62 is released and the said rod moves up under tension of spring 72. rlhis in turn releases the lever S5 and the lever is returned to normal position by coil spring 61. This action of the lever also returns the cam arm 53 to its horizontal position and likewise the collar 43 is returned to its normal horizontal position whereby the slot 44 is aligned with the shoe 42.

The invention is not to be limited to or by details of construction of the particular embodiment thereof illustrated in the drawings, as various other forms of the device will of course be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

What is claimed is:

1. 1n a printing press, the combination with a type bed mounted for vertical reciprocating movement, of an impression cylinder mounted for rotary movement and for coaction with the type bed in a manner whereby the cylinder bodily reciprocates simultaneously with the type bed but in directions opposite thereto, a main driving crank for reciprocating the bed and cylinder, a rack on the type bed, a driving gear axially mounted on the cylinder for rotation independently thereof, said driving gear having meshing relation with the rack whereby the gear is rotated first in one direction and then in an opposite direction as the type bed and cylinder reciprocate, a shaft carried by the cylinder, a pawl fixed to the shaft, a ratchet wheei lxed to the driving gear, said ratchet wheel having a notch in which the pawl is located for operatively connecting the cylinder and driving gear, a collar axially mounted adjacent one end of the cylinder for relative rotation, said collar providing a ilange having a slot leading to an annular groove, a lever fixed to the said shaft and having a shoe at its free end, said shoe when in contact with the outside surface of the iiange holding the pawl in functioning position,

whereby the cylinder and driving gear are held in connected relation, said shoe upon entering the slot for location within the groove permitting release of the pawl from its notch in the ratchet wheel, and means for eiecting limited rotation of the collar as the cylinder approaches the uppermost limit of its stroke in a printing direction whereby to shift the said slot with respect to the lever so that the slot and shoe do not align until the cylinder reaches its limit of travel in a printing direction and said crank has reached dead center position.

2. A printing press as dened by claim 1, wherein the means for effecting limited rotation of the collar for shifting the slot is cam actuated and which takes place during the last twenty degrees of the crank in reciprocating the type bed and cylinder for a printing stroke, and additionally including resilient means for returning the collar to initial position following release of the cam actuated means.

3. In a printing press having an impression cylinder mounted for intermittent rotary motion, the combination comprising, a drive member relatively movable with respect to said cylinder, releasable engaging means including a control lever for connecting the cylinder with said drive member to effect rotation of the cylinder during a portion of the operating cycle, a control member having limited relative motion between a release position and a locking position with respect to said lever, said control member when in its locking position being adapted to maintain the said lever and thereby said engaging means in its connecting position with respect to the cylinder, and means for moving the control member from its locking position to its release position to thereby release said lever and thereby said engaging means from said drive member when the cylinder reaches a predetermined angular position of rotation.

4. In a printing press the combination comprising an impression cylinder mounted for intermittent, rotary motion, a driving gear relatively movable with respect to said cylinder, means for releasably connecting said cylinder with said gear including a pawl on said cylinder and ratchet on said gear, a lever associated with said pawl, an annular hanged member having coaction with said lever to maintain said pawl engaged with said ratchet during rotation of said cylinder, a slot in said flanged member to permit movement of said lever and therewith said pawl to a disengaged position with respect to said ratchet when said cylinder rotates to a predetermined angular position, and means for temporarily displacing said flanged member and therewith said slot to preclude movement of said lever and pawl to said disengaged position until the cylinder is in said predetermined position.

References Cited in the tile of this patent UNITED STATES PATENTS 

